Method of making bits for mining machines



March 19, 1935. J WENZUCK I 1,995,234

METHOD OF MAKING BITS FOR MINING MACHINES Filed July 18, 1932 y- N" I? 4/ m Patented Mar. 19, 1935 y l I UNITED STATES PATENT OFFICE; g 1,995.23; f I f 1 v METHOD or BIT'S FOR MINING MACHINES John H. Wenzlick,Wheeling, Va., assignor to Warwood Tool Company, Wheeling, W. Va., a corporation "of 'West Virginia I Application July 18,1932, Serial No. 623,211

' Claims. (01.76108) The invention relates to new and useful imsuch as. justdescribed by the bending anddie-e provements in a method of making cuttingbits shaping of bar stock. The bar stock from which for mining machines, and moreparticularly mathe bit is made is indicated at 8 in Fig. lot the chines which are used for mining coal. drawing. This bar stock is rectangular in cross 5, An object of the invention is to provide a methsection and is dimensioned precisely as the shank 5 0d whereby bits for mining machines may be 1 of the bit which is to be formed. The bar stock made from bar stock by bending and die-shaping is placed between shaping dies or members which the bar stock to form the finishedbit.v offset the portion 8 thereof from the portion 8'- A further object of the invention is to provide thereof,leaving a connecting portion 9. The off-:

a method of forming bits from bar stockwherein setting-of one section of the bar stock from-the 10 both the lip face and the clearance face of the other is accomplished by the lateral. bodily shiftbit is made from bar stock by die-shaping. ing of the sections of the bar stock relative to In the drawing which illustrates diagrammati each other. The grain of the bar stock is indically the various steps in the improved method cated by the broken lines a, a. It will be noted Figure 1 is a side view of a bar stock from which that the grain of the bar stock after it has been 15 the bits are formed; bent to offset one section relative to another, is c Fig. 2 is an end view of the same; stillparallel with the edge face of the bar stock, Fig. 3-is a side view showing the bar stock as as-it was in the originalbar stock. After .the bar bent so' as to ofisetone portion thereof from stock has been submitted to this first shaping, another; action, it is then submitted to a die shaping 20 Fig. 4 is a side view of the bar'stock after it has means which reduces the metal along the line been submitted to die pressure for reducing the b-c (see Fig. 4) This is a diagonal line extend-i bar stock along a line extending from the outer ing from the point b, which is the outside inner inner end of one offset to the outer inner end of end of one offset portion, to the point which is the other ofiset; the outside inner end of the other oifset portion. 25

Fig. 5 is a side view showing the bar'stock after The metal is reduced along the line b-c, which it has been again submitted to die'pressure for line is to form the clearance edge of two'bits, forming the'lip faces of two bits;. the cutting endsof which are abutted and -re-': Fig. 6 is a sectional view on the line 6-6 of versed, so that the lip face of one bit is at one Fig. 5; I edge of the bar stock, whilethe lip face of the 3.0

Fig. 7 is an edge view of the bar stock as shown other bit is at the other edge of the bar stock. in Fig. 5; r Therefore, the dies are shaped so as to curve the Fig. 8 is an edge View showing the bar stock side faces of the bit leading to the line b--c. after it has been again submitted to die pressure During the first die-shaping of the bar stock,the along the same diagonal line for reducing the edge ace b w the point and 31150 35 metal connecting the clearance facesof the two tween the point b e, curves OI' bulgesvutwa bits to a thin web; 1 lengthwise of the. lip face and during the creas Fig. 9 is a perspective view of the finished bit ing, the l p f ce i urv d r. b l r swi formed by the fracturing of the connecting web This wouldmake a very poor shaping for the lip 40 shown in Fig. 8, and face of a bit, whichshould be flat or in a straight 40 Fig. 10 is a sectional view on the line 10-40 line crosswise and endwise of thelip. The bar of Fig. 9. I stock is then submitted to die-shapingalongathe The purpose of the present invention is-to form edge faces, so that these edge faces are flattened bits which are used in machines for the mining of from the point at to the point e, and also from the c 40 coal, clay and stone, and for cutting operations point b to the point e, as shown in Figures5, 6

similar thereto. The bit consists of a shank porand 7. e l tion 1 which is rectangular in cross section. The It will be noted from Fig. 6, which is a sectional cutting end 2 of the bit is provided with a lip view along .the line 66, that the edge face of face 3 and a clearance face 4. The side faces of the bar stock is fiat or straight from one side to the cutting end of the bit leading from the shank the other as indicated at 10, and the side faces are 50 to the clearance edge are curved as indicated at curved as indicated at 11, 11. This is the proper 5, 5 in Fig. 10. The cutting lip from one cutting shaping for the lip face of the bit. The side faces edge 6 to the other cutting edge 7 is flat, as clearly are curved inwardly, but there is still a substan shown in Figures 9 and 10. tially thick metal'connection- 12 between the two The method consists in the forming of a bit ends of the bits. The bar stock is then submitted 55 2 to another die-shaping step, wherein the metal is further reduced along the diagonal line b-c, so that there is only a thin web connecting the two bits as indicated at 13 in Fig. 8. The edge face 10 is still fiat, and this is to serve as the lip face of the finished bit shown in Fig. 9. The side faces are curved to a substantial meeting line which is the clearance edge of the bit. The bit is then fractured along the thin connecting web 13 and this produces the two finished bits.

From certain aspects of the invention, it may not be necessary to submit die pressure which flattens the edge face to form the flat lip face for the bit. The curved lip face in Fig. 4 may be sufficient. Itlis desirable, however, that the bar stock shall be offset by bodily shifting one portion relative to the other, so that the grain of the stock in the finished bitis par allel with the edge face face of the cutting portion of the bit. In other words, the grain of the metal in the lip portion is parallel to the lip face all the: way to the clearance edge. This avoids the slipping of the metal along the grain by. strain on the bit at the cutting point and edge. Inasmuch as the grain is parallel to the cutting edge, this strain tends to force the layers together rather than to separate and open the metal. It is also essential that the metal between the offset portions shall be shaped by die-shaping, so as to form the clearance faces of the two bits and reduce the metal so that it may be fractured along the clearance edge for the separating of the two bits and the completing of the formation thereof.

Itis obvious that the method described may be appliedfor the formingof bits having a dif-' ferent shape from that illustrated. Here again, the invention resides in the steps whereby when oncehaving selected the form of bit that is to be, made, it is accomplished solely by thebending and die-shaping of the bar stock to completely finish the bits. l

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is'- 1. The method of forming cutting bits for mining machines consisting of bending bar stock to offset one portion thereof from another while maintaining the grain of the stocksubstantially parallelto the edge faces of the bar stock, dieshaping the portion of the bar stock between the offset'portions for reducing: the same along a diagonal line from the outside inner end of one offset portion to the outside inner end of the other offset portion for shaping and forming the clearance faces of two bits connected by a thin web of metal, and fracturing said web.

2. The method of forming cutting bits for mining machines consisting of bending bar stock to oflset'one portion thereof from another while maintaining the grain of the stock substantially parallel to the edge faces of the bar stock, diethe. bar stock to the of the shank and the lip shaping the portion of the bar stock between the offset portions for reducing the same along a diagonal line from the outside inner end of one offset portion to the outside inner end, of the other offset portion for shaping and forming the clearance faces of two bits connected by a thin web of metal, die-shaping the edge portions of the bar stock -between the offset portions for flattening said edge portions and forming the lip face of two bits and fracturing, said thin web of metal to complete the formation of the bits.

3.- The'metliod of forming cutting bits for mining machines consisting in bending bar stock to offset one portion thereof from another by maintaining the grain of the stock substantially parallel to the edge faces of the bar stock, die-shaping the portion of the bar stock between the offset portions for reducing the same along a diagonal line from the outside inner end of one offset portion to the set portion, die-shaping the edge portions of the bar stock between the offset portions for flattening saidedge portionssand forming the lip face of two bits, again die-shaping the portion of the bar stock between the offset portions along a diagonal line for reducing the bar stock and completing the formation of the clearance faces of the bits, leaving a thin connecting web joining the clearance edges'of the bits and fracturing said thin web of metal to complete the formation of the bits; J

4. The method of forming cutting bits for mining machines consisting in bending bar stock to offset'one portion thereof from another by maintaining the grain of the stock substantially parallel to the edge faces of the bar stock, die-shaping the portion of the bar stock between the offset portions for reducing the same along a diagonal line from the outside inner end of one offset portion to the outside inner end of the other offset portion, die-shaping the edge portions of the bar stock between the offset portions for flattening said edge portions and forming the lip face of two bits, again die-shaping the portion of the bar stock between the offset portions along the same diagonal line for reducing the bar stock and completing the formation of the clearance faces of the bits, leaving a thin connecting web joining the clearance edges of the bits and fracturing said thin web of metal to complete the formation of the bits.

5. The method of forming cutting bits for mining machines consisting. in bending bar stock dimensioned to form-the shanks of bits so as tooffset one. portion thereof from another, dieshaping, the portion of the bar stock between the offset portions for shaping and forming the cutting end of two bits joined by a thin web of metal and fracturing said thin web of metal to complete the formation of the bits.

JOHN H.- WENZLICK.

outside inner end of the other off- 

